No Surprises Act arbitrators vary in provider win rates and payments

The No Surprises Act (NSA) banned balance billing and established an arbitration process, known as independent dispute resolution (IDR), for insurers and out-of-network providers to resolve payment disputes over out-of-network services. Publicly available IDR data only recently included arbitrator identity and still lack information about arbitrator selection.

Using novel data documenting arbitrator identities and the manner in which they were selected for cases filed in 2023 obtained in a Freedom of Information Act request, I document substantial variation across arbitrators in provider win rate, payment, wait time, case volumes, and selection methods.

The arbitrators with the highest and lowest provider win rates differed by 48 percentage points in the fraction of cases in which they choose the provider's offer. Arbitrators differ in how they are selected to decide cases; disputing parties differ in the selection methods they use to select arbitrators.

The way arbitrators are selected is an important, yet unobserved dimension of arbitration under the NSA.